The objectives of the research are: (1) to contain studies that concern the basic mechanisms associated with the effects of scorpion toxins upon membranes, particularly ion channels of conductile tissues; (2) to substantiate further and expand the model we have developed involving displacement of membrane-bound calcium as a mechanism of action for, at least, some scorpion toxins; (3) to study the structure-function relations of selected scorpion toxins, function being concerned with the physiological and immunological actions; (4) to develop methods of counteracting the effects of scorpion envenomations by antigen-antibody reactions. Venom and isolated toxins from the poisonous North American species of Centruroides sculpturatus is selected as the prototype for these studies; (5) in collaboration with colleagues at the University of Alabama in Birmingham to continue studies now in progress concerned with x-ray crystallography characterization of certain scorpion toxins and elucidation of additional amino acid sequences of toxins isolated from the venom.